21,323 research outputs found
Control of post-transplant lymphoproliferative disorders and Kaposi's sarcoma by modulation of immunosuppression
Sclerosing PEComa: A Histologic Surprise
PEComa represents a group of mesenchymal tumors consisting of perivascular epithelioid cells. We present a 50-year old female patient with a rare distinctive variant, sclerosing PEComa, characterized by extensive stromal hyalinization and a predilection for the pararenal retroperitoneum.Key Words: PEComa, Sclerosing PECom
Calculating Unknown Eigenvalues with a Quantum Algorithm
Quantum algorithms are able to solve particular problems exponentially faster
than conventional algorithms, when implemented on a quantum computer. However,
all demonstrations to date have required already knowing the answer to
construct the algorithm. We have implemented the complete quantum phase
estimation algorithm for a single qubit unitary in which the answer is
calculated by the algorithm. We use a new approach to implementing the
controlled-unitary operations that lie at the heart of the majority of quantum
algorithms that is more efficient and does not require the eigenvalues of the
unitary to be known. These results point the way to efficient quantum
simulations and quantum metrology applications in the near term, and to
factoring large numbers in the longer term. This approach is architecture
independent and thus can be used in other physical implementations
Quantum Simulation of Spin Chains Coupled to Bosonic Modes with Superconducting Circuits
We propose the implementation of a digital quantum simulation of spin chains
coupled to bosonic field modes in superconducting circuits. Gates with high
fidelities allows one to simulate a variety of Ising magnetic pairing
interactions with transverse field, Tavis-Cummings interaction between spins
and a bosonic mode, and a spin model with three-body terms. We analyze the
feasibility of the implementation in realistic circuit quantum electrodynamics
setups, where the interactions are either realized via capacitive couplings or
mediated by microwave resonators.Comment: Chapter in R. S. Anderssen et al. (eds.), Mathematics for Industry 11
(Springer Japan, 2015
Graphical evidence for the solar coronal structure during the Maunder minimum: Comparative study of the total eclipse drawings in 1706 and 1715
We discuss the significant implications of three eye-witness drawings of the total solar eclipse on 1706 May 12 in comparison with two on 1715 May 3, for our understanding of space climate change. These events took place just after what has been termed the "deep Maunder Minimum"but fall within the "extended Maunder Minimum"being in an interval when the sunspot numbers start to recover. Maria Clara Eimmert's image in 1706 is particularly important because she was both a highly accomplished astronomical observer and an excellent artist: It was thought lost and was only re-discovered in 2012. Being the earliest coronal drawings of observational value yet identified, these drawings corroborate verbal accounts a corona without significant streamers, seen at totality of this and another eclipse event in 1652 during the Maunder Minimum. The graphical evidence implies that the coronal solar magnetic field was not lost but significantly weakened and the lack of coronal structure means there was little discernable open flux (either polar or at lower latitudes) even during the recovery phase of the Maunder Minimum. These observations provide evidence for a different state of oscillation of the solar dynamo, and hence behaviour of the Sun, in comparison with that during normal solar cycle minima (when a streamer belt between two polar coronal holes is visible) or near normal sunspot maxima (when coronal structure is caused by coronal holes at all latitudes) even to observers without a telescope
Decay of Correlations in a Topological Glass
In this paper we continue the study of a topological glassy system. The state
space of the model is given by all triangulations of a sphere with nodes,
half of which are red and half are blue. Red nodes want to have 5 neighbors
while blue ones want 7. Energies of nodes with other numbers of neighbors are
supposed to be positive. The dynamics is that of flipping the diagonal between
two adjacent triangles, with a temperature dependent probability. We consider
the system at very low temperatures.
We concentrate on several new aspects of this model: Starting from a detailed
description of the stationary state, we conclude that pairs of defects (nodes
with the "wrong" degree) move with very high mobility along 1-dimensional
paths. As they wander around, they encounter single defects, which they then
move "sideways" with a geometrically defined probability. This induces a
diffusive motion of the single defects. If they meet, they annihilate, lowering
the energy of the system. We both estimate the decay of energy to equilibrium,
as well as the correlations. In particular, we find a decay like
Adding control to arbitrary unknown quantum operations
While quantum computers promise significant advantages, the complexity of
quantum algorithms remains a major technological obstacle. We have developed
and demonstrated an architecture-independent technique that simplifies adding
control qubits to arbitrary quantum operations-a requirement in many quantum
algorithms, simulations and metrology. The technique is independent of how the
operation is done, does not require knowledge of what the operation is, and
largely separates the problems of how to implement a quantum operation in the
laboratory and how to add a control. We demonstrate an entanglement-based
version in a photonic system, realizing a range of different two-qubit gates
with high fidelity.Comment: 9 pages, 8 figure
Experimental demonstration of dispersion tolerant end-to-end deep learning-based IM-DD transmission system
We experimentally demonstrate an IM-DD system relying on deep neural networks from
transmitter to receiver delivering 42 Gb/s over 20 and 40 km at 1550 nm below 3.8Ă10â3
. The ANN is
trained to tolerate deviations in dispersion by as much as Âą170ps/n
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